Malicious PDF — malware analysis report

Static analysis result for SHA-256 d18da8f5823407cf…

MALICIOUS

PDF

60.7 KB Created: 2020-07-28 04:16:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fd8d1c04d7a2d9d2d74b846fc764bd1e SHA-1: 5c899c630df86078f2f0c1f3341da5d540ac5e06 SHA-256: d18da8f5823407cfb596dc955207689c3db60be9b7f28114adf40b6baa19a82d
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a large number of embedded links, many of which point to Shopify domains, but one critical link redirects to a known malicious redirector. The document body is heavily obfuscated, but the presence of the 'chapeltown academy sixth form' keyword suggests a potential lure. The ML classifier strongly indicates maliciousness, and the link farm heuristic confirms the suspicious nature of the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://ttraff.cc/pify?keyword=chapeltown+academy+sixth+form
    • http://files.appletreecontractors.com/uploads/1/3/1/6/131607712/9709263.pdf
    • http://files.elfiesrefuge.net/uploads/1/3/2/8/132814071/338ead42a92553.pdf
    • http://files.fieldhockeygoalkeeping101.com/uploads/1/3/1/4/131483031/legorunuzoperebeb.pdf
    • https://cdn.shopify.com/s/files/1/0433/1149/7366/files/14723641166.pdf
    • https://cdn.shopify.com/s/files/1/0430/2195/9325/files/sisum.pdf
    • https://cdn.shopify.com/s/files/1/0427/5198/3772/files/17569043098.pdf
    • https://cdn.shopify.com/s/files/1/0432/7122/5502/files/jujujolaj.pdf
    • https://cdn.shopify.com/s/files/1/0431/6420/5216/files/14272105339.pdf
    • https://cdn.shopify.com/s/files/1/0432/5857/7046/files/64957727345.pdf
    • https://cdn.shopify.com/s/files/1/0431/5830/6965/files/dikim.pdf
    • https://cdn.shopify.com/s/files/1/0438/2461/1478/files/43693011329.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/66916333827.pdf
    • https://cdn.shopify.com/s/files/1/0430/8205/5842/files/19844582616.pdf
    • https://cdn.shopify.com/s/files/1/0437/7644/2519/files/43119569544.pdf
    • https://cdn.shopify.com/s/files/1/0431/6869/4432/files/baxemojigesuxusisakere.pdf
    • https://cdn.shopify.com/s/files/1/0440/7384/4888/files/33946596194.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000adc4.bin
a9d7649a0b6e879ac3bfee54b109750da0687b056a4541ba7ea039e567306b4f
pdf-font-stream PDF embedded font (sfnt) at offset 0xADC4 5468 bytes
font_01_sfnt_off0000c048.bin
018a61af446680c50caa7ec16a52cb0f38b104b511557f5919f6bd63612a2b24
pdf-font-stream PDF embedded font (sfnt) at offset 0xC048 10880 bytes